1. Field
The present invention relates to a walking robot and a method of controlling the same, and more particularly to a method of absorbing an impact generated when a foot of the walking robot lands on the ground while walking.
2. Description of the Related Art
In general, robots are machines, which conduct motions similar to those of a human being using an electrical or magnetic action. Early robots were industrial robots, such as manipulators or transfer robots, for work automation and unmanned operation in a production field, which perform dangerous jobs, simple repetitive jobs, or jobs requiring large forces. Recently, biped walking robots (hereinafter, referred to as walking robots), which have a joint system similar to that of a human being, live together with the human being in human working and living spaces, and walk with two feet, have been vigorously researched and developed.
A walking robot performs walking through the following process. First, when walking instructions, such as a walking speed, the number of steps, a step width, etc., are given, target positions and directions of both feet (right and left feet) are determined, position and direction trajectories of both feet according to time are generated based on the determined target positions and directions of the feet, and thus a walking pattern is generated. The walking robot performs walking such that positions and direction of both feet are controlled according to the walking pattern. In such a walking robot, both feet alternately land on the ground to walk, and when the foot lands on the ground, an impact is transmitted to the walking robot. In order to absorb the impact, ankle joints of the feet are respectively provided with springs and dampers, and thus an impedance control is performed such that the ankle joints have elastic characteristics. However, in the impedance control, coefficients of the springs and the dampers to adjust control characteristics are not intuitive, and it is necessary to change the coefficients of the springs and the dampers according to various walking motions. Thus, the ankles cannot have proper elastic characteristics for the absorption of the impact.